CS209072B1

CS209072B1 - Ammoniates non-continuous preparation method

Info

Publication number: CS209072B1
Application number: CS109174A
Authority: CS
Inventors: Pavol Krajci
Original assignee: Pavol Krajci
Priority date: 1974-02-15
Filing date: 1974-02-15
Publication date: 1981-10-30

Description

(54) Spdsob disKontinuálnej přípravy amoníakátov(54) Method of discontinuous preparation of ammoniacates

Vynález rieši spósob přípravy amoníakátov dís- kontinuálnym spósobom. ;The invention provides a process for the preparation of ammoniacates in a discrete continuous manner. ;

Amoniakáty, v podstatě roztoky dusičnany amonného, močoviny, alebo ich zmesi nasýtené čpavkom sú známe ako tenzné roztoky u ktorých tlak pár čpavků pri danej teplote je závislý od obsahu čpavku v pripravovanom roztoku. Ich příprava je možná kontinuálně, alebo diskontinuálne. Kontinuálnym spósobom přípravy sa zaoberá čs. patent číslo 107 681. Tento proces vyžaduje starostlivú přípravu roztokov dusičnanu amonného a močoviny o koncentrácii s malou odchylkou zloženia, ako aj temperáciu roztoku před vstupom , do reaktora. Vyžaduje pomeme zložité riešenie vlastného reaktora s vnútorným chladením a miešaním. Pre přípravu amoníakátov s vyšším obsahom čpavku, ako aj přípravu roztokov s obsahom dusičnanu amonného, močoviny s obsahom alebo bez obsahu čpavku je vhodnější diskontinuálny proces, ktorý nevyžaduje zloženie roztokov o presnej koncentrácii a ani predchádzajúcu temperáciu ! před přípravou. Jeho princip spočívá v cirkulácii i připraveného roztoku pomocou čerpadla z cirku' lačného zásobníka cez zmešovač, do ktorého sú privádzané suroviny a chladič spať do cirkulačného zásobníka. Pri doteraz známých diskontinuálnych procesoch je příprava rozdělená na štyri cykly, kde v prvom sa dávkujú suroviny, v druhom sa roztok ustaTuje a homogenizuje a v treťom sa adjustuje zloženie. Vo štvrtom sa hotový produkt odčerpává ňá sklad, alebo do přepravných zariadení. Pri postupe, pracujúceho len pod atmosférou čpavku počas odčerpávania dochádzakspátnej desorpciičpavku na rovnovážný tlak v cirkulačnej nádrži, tým k zplyneniu cirkulovaného roztoku a ku kavitácii čerpadla. Vznikajúci podtlak zvyšuje nebezpečie vniknutia vzduchu netesnosťami v systéme a tým možnosti vzniku výbušnej vzduchočpavkovej zmesi v pracovnom priestore výrobného zariadeňia. Je známy postup riešiaci tento problém, kedy prípravá je realizovaná len pod atmosférou čpavku, pričom plynný priestor cirkulačnej nádrže je prep >jený s plynným priestorom skladu vyrobeného p pduktu, konstrukčně riešeného obvykle na tlak 0,4-0,6 MPa. V danom případe plynný priestor pósobí ako pufer vyrovnávajúci tlakové změny v Systéme pri přípravě počas dávkovacieho cyklu kedy nie je teplota ustálená, ako aj pokles tlaku pri uštalovaní obsahu i odčerpávaní. Toto riešenie je vhodné len v případe že je budovaný tlakový zásobník, ako aj v případe, že tento je relativné v malej vzdialenosti od výrobnej jednotky. Pri váčších vzdialenostiach sa zvyšujú realizačně ná- klady spojené s přepojením. V případe použitia beztlakého zásobníka takéto riešenie nie je vóbec mbžné.Ammonia, essentially ammonium nitrate solutions, urea, or mixtures thereof saturated with ammonia are known as tension solutions in which the ammonia vapor pressure at a given temperature is dependent on the ammonia content of the solution being prepared. Their preparation is possible continuously or discontinuously. Continuous preparation is dealt with MS. No. 107,681. This process requires careful preparation of ammonium nitrate and urea solutions at a concentration with a small variation in composition, as well as temperature control of the solution before entering the reactor. It requires a relatively complicated solution of the actual reactor with internal cooling and stirring. For the preparation of ammoniacates with higher ammonia content, as well as for the preparation of solutions containing ammonium nitrate, urea with or without ammonia, a discontinuous process, which does not require the composition of solutions of precise concentration and prior tempering, is preferable! before preparation. Its principle consists in circulating the prepared solution by means of a pump from the circulation tank through a mixer into which the raw materials are fed and the cooler back to the circulation tank. In the known discontinuous processes, the preparation is divided into four cycles, in which the raw materials are dosed in the first, the solution is settled and homogenized in the second, and the composition is adjusted in the third. In the fourth, the finished product is pumped away from it to a warehouse or transport facility. In a process operating only under an ammonia atmosphere during pumping, a low desorption of ammonia to equilibrium pressure in the circulation tank occurs, thereby gassing the circulating solution and cavitating the pump. The resulting vacuum increases the risk of air entering the system through leakage and thus the possibility of the formation of an explosive air-ammonia mixture in the working area of the production facility. It is known to solve this problem in which the preparation is carried out only under the atmosphere of ammonia, whereby the gas space of the circulation tank is interconnected with the gas space of the warehouse of the produced product, which is usually designed to a pressure of 0.4-0.6 MPa. In the present case, the gaseous space acts as a buffer to compensate for pressure changes in the system during preparation during the dosing cycle when the temperature is not stable, as well as the pressure drop in both the content and the pumping. This solution is suitable only if a pressure reservoir is being built, as well as if it is relatively close to the production unit. At longer distances, the realization costs associated with switching are increased. In the case of using a non-pressurized container, such a solution is not at all possible.

Uvedené nedostatky, ako aj nezávislost na skladovacom zásobníku je riešená přípravou amoniakátov diskontinuálnym spósobom sýtením roztokov dusičnanu amónneho, močoviny, alebo ich zmesi s čpavkom, podfa vynálezu, podstatou ktorěhd je, že příprava sa uskutočňuje pod tlakom 0,|-1,2 MPa dusíkočpavkovej atmosféry, pričom obsah dusíka v dusíkočpavkovej atmosféře je 4 až 90/% objemových.The above drawbacks, as well as the independence of the storage container, are solved by the preparation of ammonia in a discontinuous manner by saturating the ammonium nitrate, urea or mixtures thereof with ammonia, according to the invention. atmosphere, wherein the nitrogen content in the nitrogen-ammonia atmosphere is 4 to 90% by volume.

přetlak dusíkočpavkovej atmosféry zabezpečuje celý cirkulačný systém proti vniknutiu vzduchu pri poklese tlaku nad připraveným roztokom amoniakatu pod 0,1 MPa. Minimalizuje sa desorpcia čpavku z připraveného roztoku počas odčerpávania^! a tým aj zníženie možnosti vzniku kavitácie čerpadla, umožňuje budovanie výrobnej linky nezávisle na přepojení so skladom, respektívne bez potřeby vzájomného prepojenia plynných priestorov, ako aj potřebu budovat’ tlakový zásobník v případe, že realizovaná výrobná linka je orientovaná na amoniakát s nižšou tenziou pár. To znižuje potřebu nákladov na realizáciu. Umožňuje inštalovať cirkulačně čerpadlo s menším príkonom s výtlakom len o málo váčším, ako je potřebné na prekonanie odporov v cirkulačnom systéme, čo pri správnej vofbe tlaku dusíkočpavkovej atmosféry pre prekonanie hydraulického odporu výtlačného potrubia na sklad znižuje nárok na elektrickú energiu pohonu cirkulačného čerpadla, kedže přečerpáme sa prevedie pomocou vnútomého přetlaku v cirkulačnom zásobníku. Pokles tejto energetickej náročnosti vyplývá zo vzťahu doby pripravy 180—190 minút a vyprázdnenia 30—40 minút. Uzavretosť systému výrobnej linky urýchfuje dosiahnutie rovnovážných podmienok počas chladenia nasýteného roztoku čpavkom a tým skrátenie doby potrebnej na homogenizáciu a adjustáž roztoku. Zachovává přitom výhody doposial známých postupov pripravy amoniakátov róznej kvality aj s vyšším obsahom čpavku u ktorých je tlak pár vyšší ako 0,1 MPa.overpressure of the nitrogen-ammonia atmosphere ensures the entire circulation system against the ingress of air when the pressure drops above the prepared ammonia solution below 0.1 MPa. The desorption of ammonia from the prepared solution during pumping is minimized ^! and thereby reducing the possibility of pump cavitation, allows the production line to be built independently of the warehouse interconnection, respectively without the need for interconnection of gas spaces, as well as the need to build a pressure reservoir if the realized production line is ammoniacate with lower vapor pressure. This reduces the need for implementation costs. It allows the installation of a circulating pump with less power with a displacement slightly less than that required to overcome resistances in the circulating system, reducing the pressure on the discharge pipeline to the hydraulic resistance of the discharge pipeline by correctly selecting the pressure of the ammonia atmosphere. is carried out by means of internal overpressure in the circulation tank. The decrease in this energy intensity results from the relationship between the preparation time 180-190 minutes and the emptying time 30-40 minutes. The closure of the production line system speeds up the equilibrium conditions during the cooling of the saturated solution with ammonia, thereby reducing the time required to homogenize and adjust the solution. It retains the advantages of the hitherto known processes for the preparation of ammoniacates of different quality, even with higher ammonia contents, in which the vapor pressure is higher than 0.1 MPa.

Příklad 1 t zbytku v cirkulačnom zásobníku z predchádzajúcej pripravenej šarže so zložením 19 % čpavku, 72,5 % dusičnanu amónneho s teplotou 24 °C cirkuluje čerpadlům 120 m³/hod cez zmešovač a chladič. Počiatočný tlak dusíkočpavkovej atmosféry zloženia 94,27 % čpavku, 1,2% vodných' pár, 4,52 % dusíka, nad hladinou roztoku je 0,11 MPa. Do cirkulovaného roztoku sa súčasne dávkuje 6,65 t čpavku s teplotou 15 °C a 35,43 t | 80 % roztoku dusičnanu amónneho s teplotou ;, 130 °C po dobu 35 minút. Póvodná teplota obsahu I zásobníku stúpla z teploty 24 °C na 70 °C a tlak v cirkulačnej nádrži na 0,93 MPa. Získaný roztok cirkuloval cez chladič 170 minút a ochladil sa na ' 24 °C. Tlak v cirkulačnom zásobníku sa ustálil naExample 1 t of the residue in the circulation tank from a previously prepared batch of 19% ammonia, 72.5% ammonium nitrate at 24 ° C is circulated to the 120 m ³ / h pumps through a mixer and a cooler. The initial pressure of the nitrogen-ammonia atmosphere of composition 94.27% ammonia, 1.2% water vapor, 4.52% nitrogen, above the solution level is 0.11 MPa. 6.65 tonnes of ammonia at a temperature of 15 ° C and 35.43 tonnes are simultaneously metered into the circulated solution. 80% ammonium nitrate solution at 130 ° C for 35 minutes. The original temperature of the contents of the reservoir I increased from 24 ° C to 70 ° C and the pressure in the circulation tank to 0.93 MPa. The resulting solution was circulated through a condenser for 170 minutes and cooled to 24 ° C. The pressure in the circulation tank has stabilized to

0,67 MPa. Získaný roztok s parciálnym tlakom0.67 MPa. Obtained solution with partial pressure

0,105 MPa sa přečerpal do prepravnej cisterny.0.105 MPa was pumped into a transport tank.

Příklad 2 i t zbytku v cirkulačnom zásobníku z predchádzajúcej pripravenej šarže amoniakátu so zložením' '20 % čpavku a 64,8 % dusičnanu amónneho s teplotou 24 °C cirkuluje čerpadlom 120 m³/hod cez zmešovač a chladič. Počiatočný tlak dusíko-} čpavkovej atmosféry zloženia 38,0 % čpavkuj 0,6 % vodných pár, 61,4 % dusíka nad hladinorj roztoku je 0,22 MPa. Do cirkulovaného roztoku sá súčasne dávkujú 7,15 t čpavku s teplotou 15 °(| a 27,851 80 % roztoku dusičnanu amónneho : s teplotou 130 °C po dobu 35 minút. Póvodná teplota obsahu . cirkulačného zásobníka stúpla z 24 °C na 65 °Č a tlak na 0,7 MPa. Připravený roztok cirkuloval cez chladič 150 minút a ochladil sa na 24 °C. Tlak y cirkulačnom zásobníku sa ustálil pa 0,52 MPa so zložením dusíkočpavkovej atmosféry nad roztokom 16,1 % čpavku, 0,3 % vodných pár, 83,6 % dusíka. Získaný roztok s pardalnym tlakom 0,086 MPa sa přetlačil do beztlakého zásobníka.EXAMPLE 2 It was circulated through a mixer and cooler at 120 m ³ / h through a pump at a temperature of 120 m ³ / h. The initial pressure of the nitrogen-ammonia atmosphere of composition 38,0% of ammonia is 0,6% of water vapor, 61,4% of nitrogen above the surface of the solution is 0,22 MPa. At the same time, 7.15 t of ammonia at 15 ° (| and 27.851 80% ammonium nitrate solution: at 130 ° C for 35 minutes are dosed into the circulating solution. The original temperature of the circulating tank content increased from 24 ° C to 65 ° C. and the pressure to 0.7 MPa The prepared solution was circulated through a condenser for 150 minutes and cooled to 24 [deg.] C. The pressure of the circulation tank was stabilized at 0.52 MPa with a nitrogen atmosphere composition above 16.1% ammonia, 0.3% of water vapor, 83.6% of nitrogen The solution obtained at a pulsation pressure of 0.086 MPa was transferred to a non-pressurized container.

Příklad 3 t zbytku v cirkulačnom zásobníku z predchádzajúcej pripravenej šarže so zložením 19 % čpavku, 72,5 % dusičnanu amónneho s teplotou 24 °C' cirkuluje čerpadlom 120 m³/hod cez zmešovač' a chladič. Počiatočný tlak dusíkočpavkovej atmo! sféry zloženia 30,5 % čpavku, 0,4 ‘ýó vodných pár,¹ Example 3 t of the residue in the circulation tank from a previously prepared batch of 19% ammonia, 72.5% ammonium nitrate at 24 ° C 'was circulated through a pump at 120 m ³ / h through a mixer and a cooler. Initial pressure of nitrogen ammonia atmo! spherical composition of 30.5% ammonia, 0.4% water vapor, ¹

69,1 % dusíka nad hladinou roztoku je 0,34 MPa. _sDo cirkulovaného roztoku sa súčasne dávkuje¹6,65 t čpavku s teplotou 15 °C a 35,43 t 80 % . i dusičnanu amónneho s teplotou 130 °C po dobu 35 , minút. Póvodňá teplota obsahu cirkulačného zásobníka stúpla z teploty 24 °C na 70 °C a tlak na 1,16 MPa. Získaný roztok cirkuloval cez chladič 170 minút a ochladil sa na 24 °C. Tlak v nádrži sa j ' ustálil na 1,07 MPa so zložením dusíkočpavkovej ! atmosféry 10,37 % čpavku 0,13 % vodných pár,69.1% of the nitrogen above the solution level is 0.34 MPa. To _the solution was circulated at the same rate of ¹ 6.65 tons of ammonia at 15 DEG C. and 35.43 t 80%. ammonium nitrate at 130 ° C for 35 minutes. The original temperature of the circulation tank contents increased from 24 ° C to 70 ° C and the pressure to 1.16 MPa. The resulting solution was circulated through a condenser for 170 minutes and cooled to 24 ° C. The pressure in the tank was stabilized at 1.07 MPa with the composition of nitrogen ammonia. atmosphere 10.37% ammonia 0.13% water vapor,

89,5 % dusíka. Získaný roztok s parciálnym tlakom 1,05 MPa sa přetlačil do zásobníka.89.5% nitrogen. The resulting solution with a partial pressure of 1.05 MPa was transferred to a reservoir.

Claims

The above-mentioned drawbacks as well as the storage tank independence are solved by the preparation of ammonium compounds by the discontinuous method of saturating the ammonium nitrate solution, urea, or ammonia mixtures according to the invention, the essence of which is that the preparation is carried out under pressure0, -1.2 MPa of nitrogen-containing atmosphere, with nitrogen content in the nitrogen-containing atmosphere being 4 to 90 /% by volume. Nitrogen gas overpressure securing a circulating air system against pressure drop above the prepared ammonia solution below 0.1 MPa. Desorption of ammonia from the prepared solution during pumping is minimized! and thereby reducing the possibility of cavitation, allowing the production line to be built independently of the warehouse interconnection, or the need to interconnect the gaseous spaces, as well as the need to build a pressure container in the event that the realized production line is directed to the lower vapor pressure ammonia. This reduces the need for implementation costs. It allows the circulation pump to be installed with a lower power input with only a slightly higher displacement than the need to overcome the resistances in the circulation system, which contributes to the choice of nitrogen-nitrogen atmosphere pressure to overcome the hydraulic resistance of the discharge pipe to reduce the electrical energy demand of the circulation pump drive. pumped through the internal overpressure in the circulation tank. The decrease in this energy intensity results from the relationship of the preparation time of 180-190 minutes and the discharge of 30-40 minutes. The closure of the production line system accelerates the achievement of equilibrium conditions during the cooling of the saturated solution with ammonia and thereby shortening the time required to homogenize and adjust the solution. It maintains the advantages of the hitherto known processes for preparing ammoniacal grades with higher ammonia content in which the vapor pressure is higher than 0.1 MPa. EXAMPLE 1 17 t of a residue in a circulating hopper of the previously prepared batch of 19% ammonia, 72.5% ammonium nitrate at 24 ° C circulation pumps 120 m 3 / h through a mixer cooler. The initial pressure of the nitrogen-containing atmosphere of the composition of 94.27% ammonia, 1.2% aqueous vapor, 4.52% nitrogen, above the solution level is 0.11 MPa. At the same time, 6.65 tons of ammonia at 15 ° C and 35.43 t | 80% ammonium nitrate solution at 130 ° C for 35 minutes. The initial temperature of the container contents increased from 24 ° C to 70 ° C and the pressure of the crushing tank to 0.93 MPa. The resulting solution was circulated through a condenser for 170 minutes and cooled to 24 ° C. The pressure in the circulation reservoir stabilized at 0.67 MPa. The resulting solution with a pumping pressure of 0.105 MPa was pumped into the transport tank. Example 2 and 7 t of the residue in the circulation tank of the previously prepared batch of ammonia with a composition of 20% ammonia and 64.8% ammonium nitrate at a temperature of 24 ° C circulates the pump 120 m3 / hour mixer and cooler. The initial nitrogen-ammonia pressure of the composition of 38.0% ammonia, 0.6% aqueous vapor, 61.4% nitrogen above the solution level is 0.22 MPa. At the same time, 7.15 tons of ammonia at 15 ° C and 27.851 of 80% ammonium nitrate solution are fed to the circulated solution; 130 ° C for 35 minutes. Original content temperature. of the circulation tank has risen 24 ° C to 65 ° C and pressure to 0.7 MPa. The prepared solution was circulated through a condenser for 150 minutes and cooled to 24 ° C. The pressure of the circulating reservoir stabilized at 0.52 MPa with the composition of the nitrogen-containing atmosphere over the solution of 16.1% ammonia, 0.3% aqueous vapor, 83.6% nitrogen. The resultant solution with a pressure of 0.086 MPa was forced into a pressureless container. EXAMPLE 3 7 t of the residue in the circulating tank of the previously prepared batch of 19% ammonia, 72.5% ammonium nitrate at 24 ° C circulates pumps of 120 m 3 / h through a mixer and cooler. The initial pressure of the nitrogen-containing atmosphere of the composition of 30.5% ammonia, 0.4% aqueous vapor, 1,193.1% nitrogen above the solution level is 0.34 MPa. 16.65 tons of ammonia at 15 ° C and 35.43 t of 80% ammonium nitrate at 130 ° C for 35 minutes are simultaneously dosed into the drilled solution. The original circulating tank temperature rose from 24 ° C to 70 ° C and the pressure was 1.16 MPa. The resulting solution was circulated through a cooler for 170 minutes and cooled to 24 ° C. The tank pressure stabilized at 1.07 MPa with a nitrogen-nitrogen atmosphere composition of 10.37% ammonia 0.13% water vapor, 89.5% nitrogen. The resulting solution with a pental pressure of 1.05 MPa was pushed into the reservoir. SUBJECT MATTER; A method of discontinuously preparing ammonia. by saturating solutions of ammonium nitrate, urea or a mixture thereof with ammonia, characterized in that the preparation is carried out under a pressure of 0.1-1.2 MPa in a nitrogen-containing atmosphere, wherein the nitrogen content in the nitrogen-containing atmosphere is 4-90% by volume.